Libav
mpc.c
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1 /*
2  * Musepack demuxer
3  * Copyright (c) 2006 Konstantin Shishkov
4  *
5  * This file is part of Libav.
6  *
7  * Libav is free software; you can redistribute it and/or
8  * modify it under the terms of the GNU Lesser General Public
9  * License as published by the Free Software Foundation; either
10  * version 2.1 of the License, or (at your option) any later version.
11  *
12  * Libav is distributed in the hope that it will be useful,
13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15  * Lesser General Public License for more details.
16  *
17  * You should have received a copy of the GNU Lesser General Public
18  * License along with Libav; if not, write to the Free Software
19  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
20  */
21 
23 #include "libavcodec/get_bits.h"
24 #include "avformat.h"
25 #include "internal.h"
26 #include "apetag.h"
27 #include "id3v1.h"
28 #include "libavutil/dict.h"
29 
30 #define MPC_FRAMESIZE 1152
31 #define DELAY_FRAMES 32
32 
33 static const int mpc_rate[4] = { 44100, 48000, 37800, 32000 };
34 typedef struct {
35  int64_t pos;
36  int size, skip;
37 }MPCFrame;
38 
39 typedef struct {
40  int ver;
41  uint32_t curframe, lastframe;
42  uint32_t fcount;
44  int curbits;
46 } MPCContext;
47 
48 static int mpc_probe(AVProbeData *p)
49 {
50  const uint8_t *d = p->buf;
51  if (d[0] == 'M' && d[1] == 'P' && d[2] == '+' && (d[3] == 0x17 || d[3] == 0x7))
52  return AVPROBE_SCORE_MAX;
53  return 0;
54 }
55 
57 {
58  MPCContext *c = s->priv_data;
59  AVStream *st;
60 
61  if(avio_rl24(s->pb) != MKTAG('M', 'P', '+', 0)){
62  av_log(s, AV_LOG_ERROR, "Not a Musepack file\n");
63  return AVERROR_INVALIDDATA;
64  }
65  c->ver = avio_r8(s->pb);
66  if(c->ver != 0x07 && c->ver != 0x17){
67  av_log(s, AV_LOG_ERROR, "Can demux Musepack SV7, got version %02X\n", c->ver);
68  return AVERROR_INVALIDDATA;
69  }
70  c->fcount = avio_rl32(s->pb);
71  if((int64_t)c->fcount * sizeof(MPCFrame) >= UINT_MAX){
72  av_log(s, AV_LOG_ERROR, "Too many frames, seeking is not possible\n");
73  return AVERROR_INVALIDDATA;
74  }
75  if(c->fcount){
76  c->frames = av_malloc(c->fcount * sizeof(MPCFrame));
77  if(!c->frames){
78  av_log(s, AV_LOG_ERROR, "Cannot allocate seektable\n");
79  return AVERROR(ENOMEM);
80  }
81  }else{
82  av_log(s, AV_LOG_WARNING, "Container reports no frames\n");
83  }
84  c->curframe = 0;
85  c->lastframe = -1;
86  c->curbits = 8;
87  c->frames_noted = 0;
88 
89  st = avformat_new_stream(s, NULL);
90  if (!st)
91  return AVERROR(ENOMEM);
94  st->codec->channels = 2;
96  st->codec->bits_per_coded_sample = 16;
97 
98  st->codec->extradata_size = 16;
100  avio_read(s->pb, st->codec->extradata, 16);
101  st->codec->sample_rate = mpc_rate[st->codec->extradata[2] & 3];
103  /* scan for seekpoints */
104  st->start_time = 0;
105  st->duration = c->fcount;
106 
107  /* try to read APE tags */
108  if (s->pb->seekable) {
109  int64_t pos = avio_tell(s->pb);
110  ff_ape_parse_tag(s);
112  ff_id3v1_read(s);
113  avio_seek(s->pb, pos, SEEK_SET);
114  }
115 
116  return 0;
117 }
118 
120 {
121  MPCContext *c = s->priv_data;
122  int ret, size, size2, curbits, cur = c->curframe;
123  unsigned tmp;
124  int64_t pos;
125 
126  if (c->curframe >= c->fcount && c->fcount)
127  return AVERROR_EOF;
128 
129  if(c->curframe != c->lastframe + 1){
130  avio_seek(s->pb, c->frames[c->curframe].pos, SEEK_SET);
131  c->curbits = c->frames[c->curframe].skip;
132  }
133  c->lastframe = c->curframe;
134  c->curframe++;
135  curbits = c->curbits;
136  pos = avio_tell(s->pb);
137  tmp = avio_rl32(s->pb);
138  if(curbits <= 12){
139  size2 = (tmp >> (12 - curbits)) & 0xFFFFF;
140  }else{
141  size2 = (tmp << (curbits - 12) | avio_rl32(s->pb) >> (44 - curbits)) & 0xFFFFF;
142  }
143  curbits += 20;
144  avio_seek(s->pb, pos, SEEK_SET);
145 
146  size = ((size2 + curbits + 31) & ~31) >> 3;
147  if(cur == c->frames_noted && c->fcount){
148  c->frames[cur].pos = pos;
149  c->frames[cur].size = size;
150  c->frames[cur].skip = curbits - 20;
151  av_add_index_entry(s->streams[0], cur, cur, size, 0, AVINDEX_KEYFRAME);
152  c->frames_noted++;
153  }
154  c->curbits = (curbits + size2) & 0x1F;
155 
156  if ((ret = av_new_packet(pkt, size)) < 0)
157  return ret;
158 
159  pkt->data[0] = curbits;
160  pkt->data[1] = (c->curframe > c->fcount) && c->fcount;
161  pkt->data[2] = 0;
162  pkt->data[3] = 0;
163 
164  pkt->stream_index = 0;
165  pkt->pts = cur;
166  ret = avio_read(s->pb, pkt->data + 4, size);
167  if(c->curbits)
168  avio_seek(s->pb, -4, SEEK_CUR);
169  if(ret < size){
170  av_free_packet(pkt);
171  return ret < 0 ? ret : AVERROR(EIO);
172  }
173  pkt->size = ret + 4;
174 
175  return 0;
176 }
177 
179 {
180  MPCContext *c = s->priv_data;
181 
182  av_freep(&c->frames);
183  return 0;
184 }
185 
193 static int mpc_read_seek(AVFormatContext *s, int stream_index, int64_t timestamp, int flags)
194 {
195  AVStream *st = s->streams[stream_index];
196  MPCContext *c = s->priv_data;
197  AVPacket pkt1, *pkt = &pkt1;
198  int ret;
199  int index = av_index_search_timestamp(st, timestamp - DELAY_FRAMES, flags);
200  uint32_t lastframe;
201 
202  /* if found, seek there */
203  if (index >= 0){
204  c->curframe = st->index_entries[index].pos;
205  return 0;
206  }
207  /* if timestamp is out of bounds, return error */
208  if(timestamp < 0 || timestamp >= c->fcount)
209  return -1;
210  timestamp -= DELAY_FRAMES;
211  /* seek to the furthest known position and read packets until
212  we reach desired position */
213  lastframe = c->curframe;
214  if(c->frames_noted) c->curframe = c->frames_noted - 1;
215  while(c->curframe < timestamp){
216  ret = av_read_frame(s, pkt);
217  if (ret < 0){
218  c->curframe = lastframe;
219  return ret;
220  }
221  av_free_packet(pkt);
222  }
223  return 0;
224 }
225 
226 
228  .name = "mpc",
229  .long_name = NULL_IF_CONFIG_SMALL("Musepack"),
230  .priv_data_size = sizeof(MPCContext),
236  .extensions = "mpc",
237 };
void * av_malloc(size_t size)
Allocate a block of size bytes with alignment suitable for all memory accesses (including vectors if ...
Definition: mem.c:62
#define AVERROR_INVALIDDATA
Invalid data found when processing input.
Definition: error.h:54
int size
void av_free_packet(AVPacket *pkt)
Free a packet.
Definition: avpacket.c:243
int av_add_index_entry(AVStream *st, int64_t pos, int64_t timestamp, int size, int distance, int flags)
Add an index entry into a sorted list.
Definition: utils.c:1181
#define AV_LOG_WARNING
Something somehow does not look correct.
Definition: log.h:129
void avpriv_set_pts_info(AVStream *s, int pts_wrap_bits, unsigned int pts_num, unsigned int pts_den)
Set the time base and wrapping info for a given stream.
Definition: utils.c:2829
int64_t pos
Definition: avformat.h:660
uint32_t fcount
Definition: mpc.c:42
static int read_seek(AVFormatContext *ctx, int stream_index, int64_t timestamp, int flags)
Definition: libcdio.c:153
void ff_id3v1_read(AVFormatContext *s)
Read an ID3v1 tag.
Definition: id3v1.c:227
int size
Definition: avcodec.h:974
int64_t avio_seek(AVIOContext *s, int64_t offset, int whence)
fseek() equivalent for AVIOContext.
Definition: aviobuf.c:186
AVIndexEntry * index_entries
Only used if the format does not support seeking natively.
Definition: avformat.h:878
#define AV_CH_LAYOUT_STEREO
void av_freep(void *arg)
Free a memory block which has been allocated with av_malloc(z)() or av_realloc() and set the pointer ...
Definition: mem.c:198
Format I/O context.
Definition: avformat.h:922
Public dictionary API.
static int mpc_read_packet(AVFormatContext *s, AVPacket *pkt)
Definition: mpc.c:119
uint8_t
static int mpc_read_seek(AVFormatContext *s, int stream_index, int64_t timestamp, int flags)
Seek to the given position If position is unknown but is within the limits of file then packets are s...
Definition: mpc.c:193
static int mpc_read_close(AVFormatContext *s)
Definition: mpc.c:178
uint8_t * extradata
some codecs need / can use extradata like Huffman tables.
Definition: avcodec.h:1164
AVStream * avformat_new_stream(AVFormatContext *s, const AVCodec *c)
Add a new stream to a media file.
Definition: utils.c:2521
AVStream ** streams
A list of all streams in the file.
Definition: avformat.h:990
AVDictionaryEntry * av_dict_get(const AVDictionary *m, const char *key, const AVDictionaryEntry *prev, int flags)
Get a dictionary entry with matching key.
Definition: dict.c:38
uint8_t * data
Definition: avcodec.h:973
static int flags
Definition: log.c:44
#define AVERROR_EOF
End of file.
Definition: error.h:51
bitstream reader API header.
static av_cold int read_close(AVFormatContext *ctx)
Definition: libcdio.c:145
static av_always_inline int64_t avio_tell(AVIOContext *s)
ftell() equivalent for AVIOContext.
Definition: avio.h:219
int bits_per_coded_sample
bits per sample/pixel from the demuxer (needed for huffyuv).
Definition: avcodec.h:2507
uint32_t lastframe
Definition: mpc.c:41
static const int mpc_rate[4]
Definition: mpc.c:33
MPCFrame * frames
Definition: mpc.c:43
int avio_read(AVIOContext *s, unsigned char *buf, int size)
Read size bytes from AVIOContext into buf.
Definition: aviobuf.c:452
int av_new_packet(AVPacket *pkt, int size)
Allocate the payload of a packet and initialize its fields with default values.
Definition: avpacket.c:81
#define AVINDEX_KEYFRAME
Definition: avformat.h:662
#define AV_LOG_ERROR
Something went wrong and cannot losslessly be recovered.
Definition: log.h:123
AVDictionary * metadata
Metadata that applies to the whole file.
Definition: avformat.h:1130
int frames_noted
Definition: mpc.c:45
int av_index_search_timestamp(AVStream *st, int64_t timestamp, int flags)
Get the index for a specific timestamp.
Definition: utils.c:1222
unsigned int avio_rl32(AVIOContext *s)
Definition: aviobuf.c:564
#define AVERROR(e)
Definition: error.h:43
#define NULL_IF_CONFIG_SMALL(x)
Return NULL if CONFIG_SMALL is true, otherwise the argument without modification. ...
Definition: internal.h:150
void av_log(void *avcl, int level, const char *fmt,...)
Definition: log.c:168
#define DELAY_FRAMES
Definition: mpc.c:31
int64_t ff_ape_parse_tag(AVFormatContext *s)
Read and parse an APE tag.
Definition: apetag.c:122
uint64_t channel_layout
Audio channel layout.
Definition: avcodec.h:1852
int avio_r8(AVIOContext *s)
Definition: aviobuf.c:443
AVCodecContext * codec
Codec context associated with this stream.
Definition: avformat.h:718
unsigned char * buf
Buffer must have AVPROBE_PADDING_SIZE of extra allocated bytes filled with zero.
Definition: avformat.h:397
#define FF_INPUT_BUFFER_PADDING_SIZE
Required number of additionally allocated bytes at the end of the input bitstream for decoding...
Definition: avcodec.h:531
int seekable
A combination of AVIO_SEEKABLE_ flags or 0 when the stream is not seekable.
Definition: avio.h:117
audio channel layout utility functions
uint32_t curframe
Definition: mpc.c:41
static int read_probe(AVProbeData *pd)
Definition: jvdec.c:55
int skip
Definition: mpc.c:36
AVInputFormat ff_mpc_demuxer
Definition: mpc.c:227
#define MPC_FRAMESIZE
Definition: mpc.c:30
static int read_header(FFV1Context *f)
Definition: ffv1dec.c:544
Stream structure.
Definition: avformat.h:699
NULL
Definition: eval.c:55
int64_t pos
Definition: mpc.c:35
enum AVMediaType codec_type
Definition: avcodec.h:1058
enum AVCodecID codec_id
Definition: avcodec.h:1067
int sample_rate
samples per second
Definition: avcodec.h:1791
AVIOContext * pb
I/O context.
Definition: avformat.h:964
int extradata_size
Definition: avcodec.h:1165
static int read_packet(AVFormatContext *ctx, AVPacket *pkt)
Definition: libcdio.c:114
int index
Definition: gxfenc.c:72
Definition: mpc.c:34
This structure contains the data a format has to probe a file.
Definition: avformat.h:395
int av_read_frame(AVFormatContext *s, AVPacket *pkt)
Return the next frame of a stream.
Definition: utils.c:989
int64_t duration
Decoding: duration of the stream, in stream time base.
Definition: avformat.h:756
#define AVPROBE_SCORE_MAX
maximum score
Definition: avformat.h:404
Main libavformat public API header.
static int mpc_read_header(AVFormatContext *s)
Definition: mpc.c:56
int curbits
Definition: mpc.c:44
static int mpc_probe(AVProbeData *p)
Definition: mpc.c:48
int64_t start_time
Decoding: pts of the first frame of the stream, in stream time base.
Definition: avformat.h:749
int channels
number of audio channels
Definition: avcodec.h:1792
int frames
Definition: mpc.h:63
void * priv_data
Format private data.
Definition: avformat.h:950
const char * name
A comma separated list of short names for the format.
Definition: avformat.h:525
#define AV_DICT_IGNORE_SUFFIX
Definition: dict.h:62
unsigned int avio_rl24(AVIOContext *s)
Definition: aviobuf.c:556
int stream_index
Definition: avcodec.h:975
#define MKTAG(a, b, c, d)
Definition: common.h:238
This structure stores compressed data.
Definition: avcodec.h:950
void * av_mallocz(size_t size)
Allocate a block of size bytes with alignment suitable for all memory accesses (including vectors if ...
Definition: mem.c:205
int64_t pts
Presentation timestamp in AVStream->time_base units; the time at which the decompressed packet will b...
Definition: avcodec.h:966
Definition: mpc.h:52
int ver
Definition: mpc.c:40